The anchor chain was grumbling. I awoke with a jump. Franco said the wind had changed direction and the chain was setting on its new line. Then we heard an almighty splash.

The sound was unmistakable. Two nights before, we’d just returned from our friends’ yacht and were inspecting our new rain catcher, when a beast leapt out of the water right next to Caramor and we nearly jumped out of our skins. We watched, amazed, as a manta ray banked sharply under Caramor and disappeared into the night. We were still clinging to each other from the fright!

We were out the cabin before we even realised we’d jumped out of bed. I had visions of a manta ray stranded on the coachroof.

There was nothing on deck, so we peered over the bow. Where our last anchor buoy had been, there were now three and a rope and a lot of chain. Our brains, still half asleep, scrambled to make sense of the mess, had we drifted onto someone else’s mooring? As our eyes pierced the dark, our hearts filled with dread, tangled up in our anchor chain was a large manta ray.

As you will no doubt have guessed, we try to minimise our impact on the environment. We gave a lot of thought to anchoring in coral. What was the best way to anchor to avoid damaging the fragile coral? We decided to pick up a mooring whenever possible and if not, then to buoy the anchor chain to keep it off the bottom and to reduce the risk of it wrapping around coral heads. Because our windlass is manual, we don’t have enough strength to tear through the coral, so instead Franco snorkels to see which way the chain lies and sometimes to lift it over obstacles.

Overnight the wind had dropped completely, Caramor was no longer tugging at her chain and the buoys had drifted closer together. The manta ray must have swum past as it had done before and caught the buoyed chain. To get away, it looped, and looped, and looped ... until at last the chain became so tight, the grinding woke us up.

We tried winching the chain; it was so wrapped around itself that it wouldn’t feed through the windlass, worse, it tightened the noose around the ray. At this point the manta ray was still struggling to free itself and we quickly dismissed diving as too dangerous. Franco suggested we try unravelling the chain. Using the motor we spun Caramor around her anchor until the chain loosened enough for the buoys to float to the surface. The ray stopped wriggling, as the pressure reduced, maybe it realised we were trying to help. Franco jumped into the dinghy and worked fast.

“I can see its eye,” he shouted at one point, distressed.

He was able to cut the dyneema loops that held the buoys to the clips on the chain. As the chain dropped to the bottom, the manta ray was liberated and swam off. It had taken an hour.

The poor ray was probably a little traumatised and bruised but otherwise unharmed. We were delighted when we heard it leaping out of the water again the next day.

As a result we have thought hard and long about our anchoring system and talked to other cruisers. Our conclusion is that it was a freak accident, and that we, and the manta ray, were unlucky. Our anchoring method is sound and we will continue to use it as it is much less damaging to the coral. We are just thankful we had used loops we could easily cut off.